We offer several solutions for your USP <800> needs. Our company offers products as well as certification services. Please review our MIC family of products on our website. Our MIC800N is a negative pressure unit that is fully vented. Our MIC Single is a unit that can be operated at either positive or negative pressure. The MIC Single can be externally vented and all MIC Singles currently in operation can be converted to make them externally vented. Please give us a call so we can help you with your USP <800> needs.